The Radxa CM4 is a compute module positioned as a drop-in alternative to the Raspberry Pi CM4, built around Rockchip’s new RK3576(J) octa-core Cortex-A72/A53 SoC. It is designed for edge AI and multimedia applications, offering significantly more headroom than traditional hobbyist modules.
At its core, the RK3576 integrates a 6 TOPS NPU (Neural Processing Unit) capable of accelerating AI inference tasks like image recognition and object detection at the edge. Paired with support for up to 16GB of LPDDR4X memory, the Radxa CM4 is well-suited for multitasking and heavy workloads.
Key Hardware Features
- Onboard Storage – eMMC up to 256GB for local, high-capacity data storage
- Wireless Connectivity – integrated WiFi 6 and Bluetooth 5.4 with external antenna support
- Wired Networking – Gigabit Ethernet PHY for reliable high-speed transfer
- Extended I/O – Unlike Raspberry Pi CM4’s dual 100-pin connectors, Radxa CM4 includes a third high-density connector, enabling UFS 2.0, dual PCIe Gen2, SATA 3, and DisplayPort expansion
Temperature Grades –
- Commercial version (RK3576): 0°C to 60°C
- Industrial version (RK3576J): -40°C to 85°C
- Longevity – Supply guaranteed through 2035
Radxa CM4 Block Diagram
Radxa CM4 Interfaces
Radxa CM4 Core Specifications
SoC: Rockchip RK3576 (commercial) / RK3576J (industrial)
CPU: 8 cores – 4x Cortex-A72 at 2.2GHz + 4x Cortex-A53 at 2.0GHz
GPU: ARM Mali-G52 MC3, supporting OpenGL ES 1.1–3.2, OpenCL 2.0, Vulkan 1.2
NPU: 6 TOPS (INT8), supporting mixed precision (INT4/8/16, BF16, TF32)
VPU:
Decode: H.265, VP9, AV1, AVS2 up to 8K@30fps or 4K@120fps
Encode: H.264/H.265/MJPEG up to 4K@60fps
Memory: 4GB, 8GB, or 16GB LPDDR4X
Storage: Onboard eMMC (up to 256GB), optional SPI flash footprint
Networking: WiFi 6, Bluetooth 5.4, Gigabit Ethernet PHY
Connectors: 3x 100-pin board-to-board connectors with:
Storage: 2x SATA 3.1, UFS 2.0, SDMMC
Display: HDMI 2.0 (up to 4K@120Hz), eDP (4K@60Hz), DP (4K@120Hz), 4-lane MIPI DSI (dual-display output supported)
Camera: 1x 4-lane MIPI CSI or 2x 2-lane MIPI CSI
Audio: I²S, PDM mic array support
USB: 1x USB 3.2 Gen1 OTG/Host, 1x USB 3.2 Gen2 Host
PCIe: 2x PCIe Gen2 lanes
General I/O: GPIO, I²C, SPI, UART, PWM, ADC, SDIO
Power: 5V supply
Form Factor: 55 × 40 mm
IO Board and Ecosystem
To unlock its full feature set, the Radxa CM4 can be paired with the Radxa CM4 IO board, which provides:
Storage: UFS slot, MicroSD, M.2 M-Key (NVMe SSD)
Display: HDMI, 4-lane MIPI DSI
Camera: 1x 4-lane CSI, 2x 2-lane CSI
Audio: 3.5mm jack, I²S expansion
Networking: Gigabit Ethernet RJ45 with PoE support
USB: 2x USB 2.0, 1x USB 3.0 Type-A, 1x USB 3.0 Type-C (OTG/Host)
Expansion: 14-pin GPIO + 40-pin Raspberry Pi-compatible GPIO header
Cooling & Power: Fan header, RTC battery slot, 12V DC input, PoE, onboard 5V/12V power out
Board Size: 160 × 90 mm
Additional ecosystem components include:
Radxa Camera 4K (IMX415) for high-resolution capture
Radxa UFS storage module
Radxa Display 8 HD and Radxa Display 10 FHD touch panels
Importantly, the Radxa CM4 is also compatible with Raspberry Pi CM4 IO boards and several third-party baseboards such as Waveshare CM4-NANO-B, LimeNET Micro 2.0, and others.
Radxa CM4 IO Board Interfaces
Software Support
Out of the box, the Radxa CM4 ships with Debian 12 on Rockchip Linux 6.1 kernel, tuned for stability and hardware compatibility. Advanced developers can build custom systems via Yocto Project or Buildroot, and the module also supports Android 14, opening the door to modern app frameworks and APIs.
Compatible Third-Party IO Boards
Radxa CM4 ecosystem
Market Position vs. Other CM4 Alternatives
Banana Pi BPI-CM4: Based on Amlogic A311D (6-core, 5 TOPS NPU), but software support lags behind
Orange Pi CM4: Cost-effective at just $22.9, but limited by RK3566 Cortex-A55 SoC and 0.8 TOPS NPU
Compared with these, the Radxa CM4’s RK3576 SoC, up to 16GB RAM, UFS storage, and stronger NPU make it one of the most capable Raspberry Pi CM4 replacements currently available, especially for AI workloads and industrial deployments. The deciding factor for adoption will be software maturity and long-term updates.
Availability and Pricing
The Radxa CM4 is already listed on AliExpress, with pricing depending on memory and storage configuration:
4GB RAM / 32GB storage: $70.31
16GB RAM / 128GB storage: $168.94
Radxa CM4 IO Board: $26.23
Further details, firmware updates, and documentation can be found on the Radxa Wiki and official GitHub repositories.
